Claiming electricity costs on UK returns: real examples means deducting costs only to the extent that they are incurred wholly and exclusively for taxable income, with the reporting route depending on whether your activity is miscellaneous income or a trade. Calculate the miner’s extra kWh, apportion shared bills by usage, compare actual costs with the trading allowance where relevant, and report the result in the appropriate Self Assessment entry without confusing an income deduction with CGT.
Calculate the incremental electricity used by the miner and you will have a supportable deduction from mining income.
Turn watts into an electricity cost
Convert watts to kWh by dividing watts by 1,000, then multiply by running hours and your bill’s unit rate. For example, a 3,250W ASIC running 10 hours a day for 30 days uses 3.25 × 300 = 975 kWh. At 28p per kWh, its electricity cost is 975 × £0.28 = £273.
Build a file HMRC can follow
Keep one spreadsheet row per billing period so another person can reproduce the figure in under five minutes. Include the bill dates, tariff, miner watts, hours, kWh, cost, reward dates, GBP reward values and wallet or pool transaction IDs. Save the supplier bill, smart-plug export, miner specification, hashrate log and pool statement in the same folder.
From shared household bill to claimed mining cost
1. Measure
3,250W ASIC
300 hours
2. Convert
3.25kW × 300
= 975kWh
3. Price
975kWh × £0.28
= £273
4. Report
Deduct from mining
income calculation
Compare actual costs with the £1,000 allowance
Compare your total evidenced expenses with the £1,000 trading allowance before choosing a deduction method.
Use actual costs above £1,000
Claim actual costs when the total allowable amount is more than £1,000 and you can evidence each item. A miner receives £3,400 of pool rewards, has £1,260 of metered electricity and £180 of eligible pool fees. Actual costs total £1,440, so taxable income is £3,400 less £1,440, which is £1,960.
Use the allowance when costs are lower
Use the £1,000 allowance when it is larger than your supportable costs. If rewards are £1,850 and measured electricity is £420, the allowance leaves £850 taxable. Actual costs would leave £1,430 taxable, so the allowance is £580 better in this example.
| Example | Mining income | Actual costs | Taxable with £1,000 allowance | Lower taxable figure |
|---|
| Metered ASIC and fees | £3,400 | £1,440 | £2,400 | £1,960 actual costs |
| Small home miner | £1,850 | £420 | £850 | £850 allowance |
Report rewards as income before any later CGT sale
Report each mining reward in GBP when received, then deduct eligible electricity in the Income Tax calculation.
Choose trade or miscellaneous income facts
Use self-employment reporting where mining is organised and commercial enough to amount to a trade; otherwise consider miscellaneous income. A trade is an activity run with business-like organisation and profit intent, while smaller or irregular activity may be other income. HMRC’s Cryptoassets Manual says the tax treatment depends on the facts, not the label you prefer.
Keep hardware separate from electricity
Review an ASIC or GPU separately because mining hardware may be capital expenditure rather than a running cost. Capital allowances may be relevant where the facts support a trade; do not automatically expense the full purchase price as electricity or repairs. Electricity can reduce taxable mining income, but it does not reduce the Capital Gains Tax gain when you later sell the Bitcoin.
For UK Bitcoin mining tax purposes, value each pool reward in pounds sterling when you become entitled to it or receive it, using a consistent and evidenced source. For example, if a pool pays 0.002 BTC on 14 June and the recorded GBP rate at that time is £32,000 per BTC, the taxable mining receipt is £64. That £64 is mining income even if you keep the Bitcoin rather than convert it to cash.
Keep the pool reward value, payment timestamp, transaction ID and the exchange-rate source with your UK crypto tax return records. A later sale is a separate Capital Gains Tax event, calculated from the £64 sterling acquisition value.
Whether mining is a trade is a factual question, so record the features that support the route used. A person operating one ASIC intermittently at home, with modest receipts and no wider commercial organisation, may be more likely to have miscellaneous income. By contrast, regular operations using dedicated equipment, planned capacity, separate business records, repeated pool activity and a commercial profit objective may point towards a trade.
Neither a high electricity bill nor registering as self-employed decides the issue by itself. HMRC will consider the full pattern of activity, including scale, frequency, organisation and whether the operation is carried on in a business-like way.
For Self Assessment mining income, use the self-employment pages where the facts support a trade and calculate receipts, mining income deductions and profit under the trade rules. Where the activity is not a trade, report the sterling rewards through the applicable Other UK income route in the current return journey, entering allowable expenses only where that route permits them. Check the current HMRC online prompts or paper-return notes, as labels and boxes can change.
For either route, retain a separate calculation showing Bitcoin mining costs, ASIC power consumption, metered electricity usage, household electricity apportionment, eligible pool fees and the chosen deduction method. If claiming the trading allowance, use the £1,000 deduction instead of actual HMRC allowable expenses for that same relevant income.
Avoid the evidence gaps HMRC can challenge
Prevent an HMRC challenge by making every claimed pound traceable from a supplier bill to a miner reading and then to mining income.
Reconstruct missing meter readings carefully
Reconstruct usage from rated power and dated uptime only when direct meter data is unavailable. Record why the smart-plug data is missing, use the manufacturer specification, and retain pool hashrate logs that support operating hours. A miner that was rebooted, throttled or offline needs those hours adjusted.
Exclude private and unsupported costs
Exclude household cooking, heating, lighting and any electricity costs that cannot reasonably be linked to mining. A miner running in a spare room does not justify claiming 25% of the full energy bill, even where it genuinely earned Bitcoin.
This approach is general information, not personal tax advice. Get advice if mining is through a limited company, covers several properties, uses complex business tariffs, has irregular pool payments, involves rented equipment or material sums. It also does not apply where there was no taxable mining income, you only bought Bitcoin, or electricity use cannot reasonably be linked to mining.
Frequently asked questions
Is bitcoin mining taxable in the UK?
Yes. Mining rewards can be subject to Income Tax when received, with the route depending on whether the activity is a trade or miscellaneous income.
Can I claim electricity for a miner at home?
Yes, if you can evidence the miner’s additional consumption, such as kWh from a smart plug or watts multiplied by dated operating hours. Private home use remains excluded.
Can I claim £1,000 and my electricity bill?
No. For the same mining income, choose either actual allowable expenses or the £1,000 trading allowance.
Does electricity reduce capital gains tax on Bitcoin?
No. Eligible electricity may reduce mining income when rewards are received, but it is not deducted again from the gain when Bitcoin is sold.
File the method that produces the lower taxable income without claiming more than you can evidence. Start with reward values in GBP, calculate the miner’s kWh from measured use or defensible logs, then compare total actual costs with £1,000. Save the calculation with the source records before submitting your Self Assessment return.
Where do I put mining income on self assessment?
Put it in the self-employment section if the facts show a trade, or in the relevant other UK income route if it is miscellaneous income. Keep a GBP profit calculation either way.
